Transmission Electron Aberration-free Microscope (TEAM) Project … unprecedented scientific opportunities for observing the atomic-scale order, electronic structure and dynamics of individual nanostructures … Dean Miller, Argonne National Laboratory Yimei Zhu, Brookhaven National Laboratory Ivan Petrov, Frederick-Seitz Materials Research Lab, UIUC Ulrich Dahmen, Lawrence Berkeley National Laboratory Ian M. Anderson, Oak Ridge National Laboratory Presentation to Office of Basic Energy Sciences Germantown, MD – October 3, 2002
… with implications for many important areas of science!
Feynman anticipates physical basis for chemical behavior and role of electron microscope “It would be very easy to make an analysis of any complicated chemical substance; all one would have to do would be to look at it and see where the atoms are. The only trouble is that the electron microscope is one hundred times too poor … I put this out as a challenge: Is there no way to make the electron microscope more powerful? ” – Richard P. Feynman, 1959, “There’s Plenty of Room at the Bottom” Atomic-scale imaging plays a unique role by defining quantum mechanical boundary conditions for the electronic structure calculations necessary to determine how nanostructures work
TEAM: extraordinary new scientific opportunities for direct observation of individual nanostructures • three-dimensional atomic-scale structure, shape, and defect distribution • spectroscopic identification and location of individual dopant atoms • direct imaging of the atomic-scale structure of glasses • electronic structure of individual point defects • non-spherical charge density and valence electron distribution • in-situ synthesis of novel nanoscale structures – e. g. , electron-beam lithographic removal of individual columns of atoms • in-situ observation of the synthesis of individual nanostructures • in-situ observation of processing methods – e. g. , thin film growth, oxidation, and deformation • in-situ scientific investigation of dynamic materials responses to variations in external thermodynamic variables – e. g. , temperature, pressure, stress, chemical activity, and applied electric and magnetic fields … all with unprecedented spatial, spectral & temporal resolution
Why now? A remarkable breakthrough has occurred in electron optics • Development of revolutionary aberration-correcting devices dramatically improves achievable numerical aperture in electron optical systems • This breakthrough removes the barrier that has limited the performance of the electron microscope since its invention • Simultaneous advances in stability of electronics, efficiencies of detectors, and speed of computers enable new opportunities for scientific investigation
What does aberration correction buy us? Higher probe intensity! Smaller probes! More signal! Greater sensitivity! Greater contrast!
TEAM focus: Aberration correction also buys us space! Space for controlled • Aberration correction specimen deformation! allows lenses with order of magnitude longer focal lengths at Space for 3 D specimensame resolution rotation! • Flexibility in instrument design allows in-situ studies of dynamical processes Space for in-situ synthesis & characterization • Modular approach to allow individual scientists to develop custom modules that address specific scientific questions Microscope becomes a self-contained materials science lab!
Modular sample holder configurations enable in-situ measurements of materials behavior Modular MEMS specimen holder for in situ studies Electron transparent window (Initial designs can be employed in current generation microscopes. ) Transportable specimen holder MEMS specimen Volume available for experimental tools Feed-through Wide-bodied stage Electron transparent window Front-end of stage DOE Basic Energy Sciences Microcharacterization User Centers, FS-MRL, ANL, BNL, LBL, ORNL
The TEAM project: a science-based approach for the development of aberration correction • Unique, state-of-the-art instruments designed to achieve the full potential of aberration-correcting optics – Hybrid instruments operating or on order today interface an aberration correcting device to an earlier generation microscope • Instruments tailored to in-situ scientific investigation of materials behavior at the nanoscale – Instruments designed in collaboration with non-microscopist scientists to address specific classes of scientific problems • Unique instrumentation and supporting expertise broadly available to general scientific community – Impact of investments maximized through location of instruments within outward looking user centers
Status of TEAM Project • First TEAM Workshop held following 2000 Stringer BESAC Panel Review endorsement of TEAM “vision document” • Scientific Advisory Committee established – C. B. Carter, U Minnesota; J. A. Eades, Lehigh U; J. Silcox, Cornell U; J. C. H. . Spence, Arizona State U; R. Tromp, IBM • Second TEAM Workshop, July 18 -19, 2002 at LBNL, comprised 115 participants from 47 institutions – Strong participation from microscopy and general science communities, with strong expressions of support for project • Both TEM and STEM approaches to aberration correction under commercial development – Second generation TEM & STEM aberration correctors designed • TEAM Advisory Committee recommends BES EBMCs develop full proposal to fund TEAM
Broad-based TEAM Workshop participation: 18 universities, 13 companies, 7 national labs, 8 foreign & DOE Stanford University @ Massachusetts Institute of Technology @ University of Illinois - Urbana Champaign @ Lehigh University @ Arizona State University @ University of Illinois - Chicago @ Case Western University @ North Carolina State University @ Vanderbilt University @ Northwestern University @ UC Davis @ University of Washington @ UC Santa Cruz @ UC Berkeley @ Oregon State University @ University of Minnesota @ AMD @ University of Pittsburgh @ Dupont @ Lumileds @ Gatan @ PNNL @ Hitachi @ IBM @ JEOL @ Lucent @ MMFX @ FEI @ LBNL @ LLNL @ ORNL @ BNL @ Intel @ Nion @ PGI @ ANL @ Simon Fraser University @ Chalmers University @ National Tsing Hua University @ Regensburg University @ Monash University @ University of Orsay @ CEOS @ DOE @@
TEAM 2002 Workshop: Scientific challenges identified • Nanomaterials – Dresselhaus, MIT – Synthesis, properties, assembly: electronic structure • Semiconductors – Eaglesham, Lucent – The end of the roadmap in Si technology: multiple nanoscale issues • Magnetic materials – Siegmann, ETH – Fundamental understanding + utilization of magnetic nanostructures • Photonic materials – Craford, Lumileds – Ga. N will revolutionize the lighting industry: dopants, point defects • Computational materials science – Diaz de la Rubia, LLNL – Convergence of theory and experiment: validate theory • Catalysis – Gai, Dupont – Energy, environment, transportation: controlled chemical processes Aberration correction will create fundamentally new opportunities!
Opportunity for BES Locating TEAM at existing EBMCs maximizes scientific impact • Well established user programs with missions that are aligned with BES science goals • Proximity to nation’s BES-sponsored synchrotron light and neutron sources • Closely coordinated with BES-funded Nanoscale Science Research Centers (NSRCs) • Necessary infrastructure to support unique capability – broad scientific base, advanced scientific computing, technical support, etc. • Strong record of instrumentation, technique development • Extraordinary level of coordination among EBMCs in the development of electron beam microcharacterization user centers in general, and the TEAM initiative in particular
The TEM as a materials science laboratory: atomic-scale synthesis and characterization New science enabled by TEAM: Paradigm shift from 2 D to 3 D UHV-TEM Current stateof-the-art: LEEM STM • In-situ measurements of behavior of individual nanostructures • Direct 3 D atomic-scale imaging of the synthesis of nanostructure in a controlled environment • 3 D self-assembly controlled by surface segregation – In-situ chemical probes
New science through in-situ multi-probe measurements CNT TEM • STM/AFM • Four-point probes • Indentation • Magnetic/ electric probes STM Doped nano-peapods; Yazdani, Science, 2002. e-
Science of catalysts: 3 D atomic-scale morphology, composition, and chemical state Current state-of-the-art: At right, fuel cell Cu/Zn. O catalyst particles changing shape in response to gaseous environment; Hansen et al. , Science 295, 2055 (2002). New science enabled by TEAM: Model system for redox catalysis: Oxidation of CO by Pt on titania Key Scientific Questions: • How does 3 D morphology of catalyst particle and its wetting to oxide support vary with T, {pi}, i = O 2, CO 2, etc. ? • How is oxygen transported to particles to effect redox reaction (e. g. , CO to CO 2)? • What is physical extent of chemically reduced area of substrate in vicinity of active metal particle?
Science of semiconductors: 3 D atomic-scale elemental distribution and nanoscale structure Current state-of-the-art: New science enabled by TEAM: Local 3 D elemental distribution through: • Atomic resolution TEM & STEM tomography • Single atom sensitivity in STEM across most of periodic table Local nanoscale structure through: • Nanocrystallography P. M. Voyles, D. A. Muller et al. , Nature 416, 826 (2002) Local elemental distribution key to developing Ga. N for solid state lighting; N, O distribution, amorphous material key for Si gate oxide
Science of superconductors: simultaneous imaging of structural defects, magnetic fields Current state-of-the-art: Lorentz micrograph of chain-lattice state of vortices in Bi-2212 film SCIENCE 294, 5549, 2136 (2001) New science enabled by TEAM: ● Location of vortices relative to “pinning” structural defects via simultaneous high resolution and magnetic imaging ● Magnetic structure in vortex core ● Proximity effects at interfaces (e. g. , magnetic superconducting) Methods ● ● Resolution limit of 2 nm insufficient for simultaneous imaging of structural defects ● ● ● Phase reconstruction (Coene, Thust): defocus series enable long exp. times Cs-corrected Lorentz TEM Electron Holography Lorentz STEM (0. 1 nm dedicated)
Science of nanoscale functional materials: non-spherical charge density, electron orbitals & spin Current state-of-the-art: B B Valence electron distribution in Mg. B 2. Left: 2 D line H=170 Oe 35 Oe H=300 Oe contour; Right: 3 D map New science enabled by TEAM: • Non-spherical charge density & electron orbitals via quantitative small-angle electron scattering • Structure, bonding in aperiodic and amorphous materials • Scientific understanding of spin dynamics & switching behavior of magnetic nano-arrays Methods ● ● Local magnetization & induction distribution of magnetic Co arrays ● Development of ultra-fast (104 frames/s) solid-state detector Position-sensitive, coherent interferometric diffraction for 5 D structure (3 r + 2 q) Real-time phase retrieval for in-situ mapping of electro- & magneto-static potential, field
Conclusion: TEAM will enable scientific discovery that can’t otherwise be achieved • Science-based approach for the development of aberration correcting electron optics • Unique in providing 3 D atomic-scale structure and dynamics of individual nanostructures – From 2 D to 3 D; from atomic columns to atoms ; from static to dynamic • TEAM concept transforms electron microscope from imaging instrument into self-contained materials science laboratory – Individual scientists able to develop experimental modules that interface with unique TEAM microscopes to address specific scientific questions • New opportunities for materials discovery through combined atomic-scale characterization and in-situ synthesis – Direct observation of nanoscale synthesis at atomic resolution • Feynman’s Holy Grail: unique role by defining the quantum mechanical boundary conditions for the electronic structure calculations necessary to determine how nanostructures work
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